1d • Paramedic Talk
12-Lead ECG Essentials
How's your 12 lead knowledge? I've been hearing from a lot of students that these topics are a must know on your national.
Bipolar Leads (Leads I, II, III)
What they are:
Measure electrical activity between two electrodes
The 3 Bipolar Leads
- Lead I → Right arm → Left arm
- Lead II → Right arm → Left leg
- Lead III → Left arm → Left leg
What they show:
- Frontal plane view of the heart
High-Yield Associations
- Lead II → most commonly used for rhythm monitoring
- Leads II, III, aVF → inferior wall
NREMT Pearl: Bipolar leads = limb-to-limb electrical comparison
Augmented Leads (aVR, aVL, aVF)
What they are:
Measure electrical activity from one positive electrode looking toward the heart
The Key Augmented Leads
- aVF → looks at inferior wall
- aVL → looks at lateral wall
- aVR → generally not used for localization (but clinically important in some cases)
High-Yield Associations
- Inferior leads → II, III, aVF
- High lateral leads → I, aVL
NREMT Pearl: aVF = feet → inferior heart
When to Check a V4R (Right-Sided ECG)
Indication: Inferior STEMI
Why?
- Inferior MIs can involve the right ventricle
What V4R tells you:
- Confirms right ventricular infarction
Why this matters
Right-sided MI patients are:
- Preload dependent
Clinical Impact
- ❌ Avoid nitrates (can cause severe hypotension)
- ✔️ Give fluids to maintain preload
NREMT Pearl: Inferior MI → check V4R before giving nitro
Reciprocal Changes
What they are:
ST depression in leads opposite the area of infarction
Why they matter:
- Help confirm true STEMI
- Increase diagnostic accuracy
MUST KNOW PATTERNS
Inferior MI
- ST elevation: II, III, aVF
- Reciprocal depression: I, aVL
Lateral MI
- ST elevation: I, aVL, V5, V6
- Reciprocal depression: II, III, aVF
Posterior MI
- V1–V3 depression = posterior involvement
NREMT Pearl: ST elevation in one area → look for depression opposite
Delta Wave
What it is:
Slurred upstroke at the beginning of the QRS complex
What it indicates:
Accessory pathway (pre-excitation)
Classic Condition:
- Wolff-Parkinson-White (WPW)
ECG Findings
- Short PR interval
- Delta wave
- Wide QRS
Why it matters:
- Can lead to dangerous tachydysrhythmias
NREMT Pearl: Delta wave = WPW = accessory pathway
Summary
- Bipolar leads (I, II, III) → limb-to-limb view
- Augmented leads (aVL, aVF) → single-point perspective
- Inferior MI → check V4R before nitro
- Reciprocal changes confirm STEMI
- Delta wave = WPW
7:12
2
0 comments
12-Lead ECG Essentials
skool.com/rescueacademy
Calling ALL future EMTs & Paramedics. Let's PASS the National Registry on the FIRST attempt.
Leaderboard (30-day)
1
+9
2
+4
3
+4
4
+2
5
+2
Powered by